Startrack - what is it about?

tl;dr

Startrack was a hardware for Atari computers, which I developed in the 1990s. It is about a professional audio card for the VME bus of these computers. There was also software with which you can record, edit audio, arrange in tracks, and then spend the audio card in very high quality. The audio card worked on the Atari TT, but only more powerful hardware like a Hades 060, or a Milan had the power, which was needed in order to be able to work smoothly with many traces at the same time. This article documents the development of this hardware and software, prototypes, the variants in hardware and software, as well as the expansion with additional interfaces.

Startrack is a professional audio card for the VME bus of the Atari TT, as well as fast, compatible computers such as Hades 060 and Milan.

Back in 1994 I would have liked to have had an audio card for my newly acquired Medusa 040 computer. The Medusa 040 was a fast Atari ST clone with Motorola MC68040 CPU.
Unfortunately, I quickly found that such hardware did not exist in the quality that I imagined. There were only sound blaster-like sound cards that couldn't do much and didn't sound particularly good.
So I started to construct and build such an audio card personally for me. The structure was carried out on a hole grid board. The first question for me was which audio -controller ICS I could use, which can also offer an excellent sound. I therefore screwed up my CD player and my DAT recorder and looked at what was used in these devices. Crystal chips were used in both hi-fi components. So I got the component catalog for Crystal audio converter, and then selected the right ADC and DAC ICs for my project.
At that time I had already gained some experience with the corresponding tools, which you needed for such a project. For measurements I had a 3 channel oscilloscope from Hameg, a (naturally) self -made soldering station of ELV, as well as a multimeter. I knew Pals and Gals from Lattice and had the right, still relatively cheap hardware and software to program them with my own logic.
It quickly turned out that my Atari Mega Ste had problems pushing the data quickly enough to the audio converter. Data packages were lost again and again. This happened especially when the computer had to do other tasks. Therefore, I used large, fast FIFO buffers, which could temporarily store the data for a short time. So the problem was off the table.

The Atari Messe in 1994 was due in Bonn. I took the prototype to the fair to find out whether there is already software that could possibly be adjusted for the audio card and whether there is an interest in the players of the Atari scene. I had noticed a great interest at the MW Computer exhibition stand there, and the conversation was very good. In the course of the conversation, it quickly became clear that the audio card would be much more interesting if it had a DSP and compatibility with Atari Falcon. Here, a collaboration with MW computer was scheduled, which later also took over the sales of the audio card. In the period that followed, I started to drill the audio card with a DSP accordingly. For this, the Atari Falcon documentation, which I was provided with by MW Computer, was very helpful.

However, there was still a lot of work ahead of me: it should be the DSP56002 from Motorola, but it was difficult to get. I therefore built the prototype with an existing DSP56001. I bought this a year or two earlier at the 'Hobby and Electronics' trade fair in Stuttgart. At that time that was an excellent point of contact for exotic components. This was also available in a pin grid version, so it could be built on a hole grid board. This would have been much more difficult as a SMD construction element. I also had to familiarize myself with the special assembler language. The DSP can carry out several commands at the same time, but not in any combination. These commands had to be coordinated to get an optimal execution speed. Motorola had a small and cheap development system where the hardware is already fully built up and the hardware could be connected to a PC. This was very helpful to be able to test some small effect programs in advance.
All in all, that was a lot of work. When the hardware was too well developed, the project made a 'product' to make the project.

A board had to be developed or actually there were even 2 boards. The DSP part was attached to the audio card. It was also fully functional without a DSP. But then without compatibility with Atari Falcon, which presupposed a DSP56001. Many programs for the Atari Falcon used the DSP, so that the audio card had to do without these programs without DSP.
Therefore, the audio card was ultimately always sold with DSP. Due to the modular concept, other, more powerful DSPs could have been used later.

The audio card made the DSP much more expensive. But hey, you wanted a high-end product. You got that too. There were also some Falcon programs on this, which would not have been possible without DSP.
The 4-layer boards were completely developed with the Atari ST software Plato, and also produced via Gerber export and control of the automatic stocks.
The program was really first -class, there were no crashes or serious mistakes. Only the production of the layers for the power supply was problematic. The insulation rings for the overtactations of the layers were missing when the tanner edition was not issued. Unfortunately, that was not noticeable in time. This made the first test production of 4 boards directly for the bin.
The second attempt was fine. I soldered the first board manually by hand. After all, I wanted to make sure that there were no hidden mistakes here.
There were also a few minor wiring errors, but, with a little copper lacquer wire, were easy to correct in a few places. Overall, however, you could be very satisfied.
There were no serious mistakes here, even the DSP card worked perfectly. In view of the complexity of the circuit, this was an excellent result in my opinion.
The multiple examination of the board layout paid off significantly.

 

 

Now the audio card in Hades 060 computer could be tested for the first time.

All data on the project including circuit boards and software can be found on my Github repository.